Conventionally, relatively small-scale data processing devices, such as personal computers, have been normally used independently. However, owing to the recent improvement in data throughput and the recent tendency in down-sizing, construction of a distributed processing system by connecting a plurality of data processing devices within a specific area in a company or a department to form a network or construction of a simple network rather than performing a distributed processing, for example, has been frequently performed for effectively using accumulated data.
Such a network is generally called a LAN. The simplest LAN construction includes an arrangement wherein a network OS (Operating System) and peer-to-peer 10BASE2 or 10BASE-T, etc. are combined. Among them, the LAN connection based on 10BASE-T is relatively simple and can be carried out at a user side without asking an expert. For this reason, upon constructing the LAN based on 10BASE-T, the wiring thereof has been often done by the user individually.
However, even though the 10BASE-T wiring is so easy, if there is a wiring miss, the network does not work. Further, as a scale of the LAN increases, the number of cables also increases so that the wiring thereof becomes complicated. Under these circumstances, if, for example, a fault, such as cable disconnection or misfiring, occurs, a procedure is necessary for finding which cable is subjected to the fault. For such a procedure, a method has been used, wherein loopback connectors are connected to both ends of each cable and a dedicated cable tester including a loop resistance, etc. is connected, and then a conduction test is carried out relative to each cable, so that presence/absence of disconnection or misfiring can be confirmed per cable to search for a cable which is subjected to the fault.
However, in such a conventional disconnected cable searching method, it is necessary to connect the loopback connectors to both ends of a cable to be tested. In order to connect, after connecting a loopback connector to one end, a loop back connector also to the other end, an operation is necessary for tracing the cable having the loopback connector connected to one end thereof. This operation for finding out the cable to which the loopback connector is connected is an awful operation in the complicated wiring. Thus, the conventional conduction test requires extremely large labor for finding the fault.
Further, a problem is raised, wherein the connecting operation for the loopback connector for performing the conduction test causes a new fault, such as misconnection or contact failure, etc. Moreover, the conventional conduction test has a problem that only a test for cable can be achieved, and a connection confirmation test inclusive of a HUB, etc. can not be achieved.
The present invention has a subject to solve the foregoing problems and to provide a LAN tester which is capable of carrying out a cable conduction test and a miswiring confirmation test as well as a simple operation test inclusive of a HUB, etc. only at one end.